[LUCENE-10544] Should ExitableTermsEnum wrap postings and impacts?

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: core/index
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Greg Miller
• Created: 28/Apr/22 14:37
• Updated: 28/Aug/22 16:40

Description

While looking into options for LUCENE-10151, I noticed that ExitableDirectoryReader doesn't actually do any timeout checking once you start iterating postings/impacts. It does create a ExitableTermsEnum wrapper when loading a TermsEnum, but that wrapper doesn't do anything to wrap postings or impacts. So timeouts will be enforced when moving to the "next" term, but not when iterating the postings/impacts associated with a term.

I think we ought to wrap the postings/impacts as well with some form of timeout checking so timeouts can be enforced on long-running queries. I'm not sure why this wasn't done originally (back in 2014), but it was questioned back in 2020 on the original Jira SOLR-5986. Does anyone know of a good reason why we shouldn't enforce timeouts in this way?

Related, we may also want to wrap things like seekExact and seekCeil given that only next is being wrapped currently.